biopsych Flashcards

Question

Answer 1

Brain plasticity (or neuroplasticity) refers to the brain’s ability to change and adapt as a result of experience, learning, or injury. It can involve: The strengthening of existing neural connections. The formation of new connections and pathways. Plasticity occurs throughout life but is most pronounced during childhood when the brain is highly adaptable. Evidence: Maguire et al. (2000): Studied London taxi drivers using brain scans. Found significantly more grey matter in the posterior hippocampus (linked to spatial navigation) than in controls. The longer they had been driving, the more structural changes were seen. This shows that the brain can reorganise itself in response to environmental demands. Functional Recovery After brain injury or trauma (e.g. stroke, accident), unaffected areas of the brain can adapt and compensate for lost functions — a form of plasticity known as functional recovery. The brain is able to rewire and reorganise itself by forming new synaptic connections close to the area of damage. this process is supported by a number of structural changes in the brain including: - Axonal sprouting: New nerve endings grow and form new synapses. - Recruitment of homologous areas: The opposite hemisphere may take over the function of the damaged area. - Denervation supersensitivity: when axons do a similar job become aroused to a higher level to compenstate for the ones that are lost. One major strength of research into plasticity and functional recovery is its direct practical application in clinical settings. Understanding that the brain can reorganise itself following trauma has led to the development of neurorehabilitation techniques designed to maximise recovery. For instance, therapies such as constraint-induced movement therapy (which forces the use of an impaired limb) or transcranial magnetic stimulation (to rewire damaged circuits) help stimulate functional recovery by promoting the brain’s natural plasticity. This has important implications for patients recovering from strokes, brain injuries, or surgery, making this research socially and economically valuable. The ability to translate theoretical understanding into real-world interventions supports the external validity of plasticity research and demonstrates psychology's positive contribution to medicine. ✅ 2. Scientific and Objective Evidence Research into brain plasticity is supported by highly objective and scientific methodologies, increasing the reliability and validity of findings. Techniques such as fMRI (functional magnetic resonance imaging) and EEG (electroencephalogram) allow researchers to observe the brain’s structure and function in real time with great precision. For example, Maguire et al. (2000) used MRI scans to demonstrate that London taxi drivers had significantly more grey matter in the posterior hippocampus, an area linked to spatial navigation. This structural change was positively correlated with the amount of time spent driving, providing clear support for experience-dependent plasticity. The use of such sophisticated technology allows for more accurate, replicable data and gives neuroscience a solid empirical foundation, helping it gain credibility as a rigorous scientific discipline. ❌ 4. Individual Differences in Plasticity and Recovery Not all individuals experience the same level of functional recovery, suggesting that plasticity has limits and is influenced by individual factors. For example, age appears to play a crucial role. The brain is thought to be more plastic during childhood, when synaptic pruning and formation occur more rapidly. Elbert et al. (2001) found that the capacity for plasticity is significantly higher in children than in adults, indicating a critical period for recovery. In addition, Schneider et al. (2014) found that patients with a college-level education were seven times more likely to be disability-free one year after a traumatic brain injury compared to those who had not completed secondary education. This suggests that cognitive reserve — built through education and mental stimulation — significantly affects recovery outcomes. These findings underline that brain plasticity and recovery are not universally effective and must be understood within the context of individual variation. ❌ 5. Lack of Long-Term Research and Predictive Power While there is strong evidence for short-term functional recovery, less is known about the long-term sustainability of these changes. Some studies suggest that initial improvements may plateau or even reverse over time, especially without continued intervention. Moreover, many studies in this area are case studies or small-scale, meaning they lack the statistical power to predict outcomes across diverse populations. The process of plasticity is also complex and not fully understood; it is difficult to determine which neural changes are directly responsible for behavioural recovery. As a result, although functional recovery can be observed, predicting its success in any individual case remains limited. This reduces the predictive validity of current research and indicates a need for more longitudinal and large-scale studies.

Answer 2

➤ 1. fMRI (Functional Magnetic Resonance Imaging) Measures changes in blood oxygenation and flow when a person performs a task. Active brain areas use more oxygen; fMRI produces 3D images showing which areas are active (localisation of function). Example: Used to study language processing, memory, and emotion in real-time. ➤ 2. EEG (Electroencephalogram) Measures electrical activity in the brain via electrodes placed on the scalp. Produces brain wave patterns used to detect unusual activity (e.g., epilepsy, sleep stages). Example: Used in sleep studies and diagnosing seizure disorders. ➤ 3. ERPs (Event-Related Potentials) A type of EEG that measures brain responses to specific stimuli (e.g., sounds, images). Uses statistical averaging to filter out background activity, leaving only the stimulus-linked response. Example: Used to study attention, decision-making, and perception. ➤ 4. Post-Mortem Examinations Analysis of a person’s brain after death, often used in people with rare conditions. Brain is examined for structural abnormalities or damage linked to behaviour or deficits during life. Example: Broca’s post-mortem study of “Tan” revealed damage to left frontal lobe, supporting localisation of speech. 🔸 AO3: In-Depth Evaluation of Brain Study Methods ✅ 1. fMRI – Strengths Non-invasive and does not use radiation, making it safe. Produces images with high spatial resolution (about 1–2 mm), allowing precise localisation of brain activity. Provides a dynamic (live) picture of the brain. However: - Has poor temporal resolution (5–10 seconds delay between brain activity and image). - Measures blood flow, not direct neural activity — an indirect measure. ✅ 2. EEG – Strengths Excellent temporal resolution — detects activity changes to the millisecond. - Useful in clinical diagnosis, e.g. epilepsy, and in understanding sleep cycles. However: - Poor spatial resolution — can’t pinpoint exact brain structures involved. - Electrical signals are picked up from many neurons — hard to isolate exact sources of activity. ✅ 3. ERPs – Strengths Combines high temporal resolution (like EEG) with ability to pinpoint response to specific stimuli. - Useful for cognitive research, e.g. investigating attention, language, and sensory processing. However: - Requires many trials to produce reliable data (as background noise must be filtered out). - Interpretation can be complex and subjective, depending on experimental controls. ✅ 4. Post-Mortems – Strengths Allow for detailed examination of physical brain structure. - Has provided foundation for many early discoveries in brain science (e.g., Broca and Wernicke). However: - Only provides retrospective information — can’t measure brain activity or function at the time of behaviour. - Hard to establish causation — damage found may not be directly linked to the behaviour observed. - Ethical issues may arise, especially with informed consent (e.g., historical case studies).

Answer 3

Circadian rhythms are biological cycles that last approximately 24 hours and repeat daily. The key circadian rhythm you need to know is: ⏰ 1. Sleep–Wake Cycle Controlled by the suprachiasmatic nucleus (SCN) in the hypothalamus. The SCN responds to light levels and helps regulate melatonin production via the pineal gland. At night, melatonin is increased to promote sleep; during daylight, melatonin is suppressed, promoting wakefulness. 🧑‍🔬 Siffre (1975) Lived in a cave with no natural light or time cues for 6 months. His sleep-wake cycle settled into a rhythm of around 25 hours, showing the existence of an endogenous pacemaker (internal clock). However, the cycle was slightly longer than 24 hours, showing the importance of external cues (e.g., light) in adjusting the cycle. 🧪 Aschoff and Wever (1976) Participants lived in a bunker without natural light. Most developed circadian rhythms around 24–25 hours, supporting Siffre’s findings. ✅ 1. Real-World Applications – Shift Work and Health Understanding circadian rhythms has practical applications in improving workplace efficiency and health. Research has shown that disruption to circadian rhythms (e.g., night shifts) can lead to health problems, including heart disease, depression, and increased accidents. For instance, Boivin et al. (1996) found that night-shift workers had reduced alertness at around 6 a.m. This research is useful for informing shift scheduling, improving worker safety, and promoting occupational health. ✅ 2. Useful in Medical Research and Drug Treatments Circadian rhythms also inform chronotherapeutics – the timing of drug treatments. For example, some medications (like chemotherapy or blood pressure drugs) are more effective if taken at certain times of day. This shows how understanding biological rhythms can have life-saving applications in medicine, increasing the ecological and practical validity of the research. ❌ 3. Methodological Issues in Case Studies Key studies like Siffre’s are based on small samples or case studies, often involving just one person in artificial conditions. This makes it difficult to generalise the findings to the wider population. For example, Siffre later admitted that his internal clock slowed down with age, suggesting individual differences are significant. As such, results may not apply universally. ❌ 4. Artificial Conditions and Lack of Ecological Validity Studies that isolate participants from natural light (e.g., bunkers or caves) involve highly artificial environments. This may affect participants’ stress levels, sleep quality, and general behaviour, potentially confounding the results. The lack of real-world relevance limits the external validity of such findings. ❌ 5. Individual Differences in Circadian Rhythms There are notable individual differences in circadian rhythms. For example, Duffy et al. (2001) found that some people are naturally “morning people” (larks), while others are “night owls.” Age also plays a role, as teenagers often have a delayed sleep phase. This variation suggests that one-size-fits-all explanations of circadian rhythms are overly simplistic and need to account for genetic and developmental factors.

Answer 4

Infradian rhythms are biological rhythms that last longer than 24 hours. They may occur weekly, monthly, or even annually. ➤ Key Infradian Rhythms to Know: 1. The Menstrual Cycle An infradian rhythm lasting approximately 28 days, regulated by hormones such as oestrogen and progesterone. These hormones prepare the uterus for pregnancy by causing ovulation and thickening the womb lining. Controlled by endogenous factors (hormones), but can be influenced by exogenous cues, such as pheromones. ⏳ McClintock (1998) – Research on Menstrual Synchrony Studied 29 women with irregular cycles. Pheromones were collected from women at different stages of their cycle and applied to other women’s upper lips. 68% of participants experienced changes to their cycle that brought them closer to the cycle of the pheromone donor. This suggests synchronisation of menstrual cycles can occur via exogenous zeitgebers like pheromones. 2. Seasonal Affective Disorder (SAD) A type of depression that occurs in a seasonal pattern, typically during winter months when daylight hours are shorter. Thought to be linked to melatonin – the pineal gland produces more melatonin in darkness, which may suppress serotonin production and lead to low mood. SAD is considered a circannual rhythm (yearly), but also has features of a circadian disruption (due to reduced daylight). ✅ 1. Research Support for Hormonal and Pheromonal Influence McClintock’s study supports the role of exogenous cues (like pheromones) in regulating infradian rhythms. Her findings suggest that biological rhythms, while driven internally, can be influenced by social and environmental factors. This supports the interactionist approach in biopsychology, showing that both endogenous and exogenous factors are important in understanding infradian rhythms. ❌ 2. Methodological Issues in Synchrony Research Despite McClintock’s findings, methodological criticisms have been raised: The study was not tightly controlled – other factors such as diet, stress, and exercise may also influence menstrual cycles. Sample size was small and the effects modest. Critics argue the evidence for menstrual synchrony is inconsistent, and chance may account for some synchronisation. For example, Trevathan et al. (1993) found no evidence of synchrony in a large sample of women living together. This raises concerns about the validity and replicability of synchrony research. ✅ 3. Real-World Application – Treatment of SAD Understanding SAD as an infradian rhythm has led to effective treatments such as phototherapy (exposure to bright artificial light). Phototherapy is shown to reset melatonin levels and relieve symptoms in up to 60% of sufferers. This supports the role of light as an exogenous zeitgeber influencing infradian rhythms and highlights useful, practical applications of this research in treating mental health conditions. ❌ 4. Evolutionary Perspective – Menstrual Synchrony May Not Be Adaptive Some argue that menstrual synchrony has evolutionary value — for example, it may have helped women nurture offspring collectively by synchronising pregnancies. However, others question this: If all females in a group ovulate at the same time, this may increase competition for the most genetically fit males. From an evolutionary standpoint, asynchrony may be more beneficial for reproductive success. This debate challenges the assumption that synchronisation is a biologically adaptive trait. ❌ 5. Reductionism – Oversimplifying SAD While SAD is linked to melatonin, this biological explanation may be too reductionist. Psychological and social factors such as reduced social contact or negative thinking during winter — may also contribute. This means that holistic models (including both biological and environmental factors) might better explain SAD than purely biological accounts, highlighting the need for an interactionist approach.

Answer 5

Ultradian rhythms are biological cycles that occur more than once in a 24-hour period. These rhythms are shorter than a day and repeat frequently. ➤ Key Ultradian Rhythm: The Sleep Cycle The most commonly studied ultradian rhythm is the sleep cycle, which repeats approximately every 90 minutes during the night. ➤ Stages of the Sleep Cycle: Sleep is made up of five distinct stages, which cycle through approximately 4–6 times per night. Stage 1 (Light Sleep) – Alpha/theta waves, easily woken. Stage 2 – Slightly deeper sleep; sleep spindles and K-complexes appear. Stage 3 (Deep Sleep) – Delta waves, body begins to repair. Stage 4 (Very Deep Sleep) – Mostly delta waves; restorative. REM Sleep (Rapid Eye Movement) – Brain is active, dreaming occurs, body is paralysed. REM sleep increases in length throughout the night. The cycle of stages 1–4 followed by REM is an example of an ultradian rhythm. ➤ Research Evidence: Dement and Kleitman (1957) Monitored 9 adults during sleep using EEG recordings. Found regular patterns of brain activity corresponding to different stages of sleep. REM sleep was strongly associated with dreaming — participants awoken during REM were more likely to recall dreams. ✅ This provided objective evidence for the ultradian structure of the sleep cycle. 🔸 AO3: Evaluation of Ultradian Rhythms ✅ 1. Scientific and Objective Evidence Research into ultradian rhythms (e.g. by Dement & Kleitman) uses controlled lab settings and scientific equipment like EEGs to monitor brain waves. This allows for precise, objective, and replicable measurements of sleep stages. The use of technology enhances the scientific credibility of research and supports the idea that the sleep cycle follows a regular, biological rhythm. ✅ 2. Support from Individual Differences in Sleep Although the sleep cycle generally follows a 90-minute rhythm, individual differences are common and meaningful. Tucker et al. (2007) found significant differences in the duration of each sleep stage between participants, even under controlled conditions. This suggests that ultradian rhythms are influenced by both biological and possibly genetic factors, supporting the idea that there is variation within a general biological framework. ❌ 3. Artificial Lab Conditions Many studies on sleep cycles, including Dement and Kleitman’s, are conducted in sleep laboratories where participants are connected to EEGs and may be disturbed during the night. These artificial settings may impact the natural sleep cycle due to lack of ecological validity, stress, or discomfort. As a result, the findings may not fully represent how sleep works in everyday life. ❌ 4. Limited Understanding of REM Sleep Functions While REM sleep is linked to dreaming and memory consolidation, its exact purpose is still debated. Some researchers argue REM is essential for emotional processing or cognitive development, but evidence is not conclusive. This limits our understanding of why ultradian rhythms exist and what function they serve. ✅ 5. Real-World Applications: Sleep and Mental Health Understanding ultradian rhythms, particularly the sleep cycle, has important applications in treating sleep disorders, mental health problems, and optimising performance. For example, disruptions in REM sleep have been linked to conditions such as depression and anxiety. Improving knowledge of these patterns allows for more targeted therapies and lifestyle interventions.

Answer 6

These are mechanisms that regulate biological rhythms, such as the circadian sleep–wake cycle. ➤ What Are Endogenous Pacemakers? Endogenous pacemakers are internal biological clocks that help regulate our biological rhythms without external cues. 🧠 Key Example: The Suprachiasmatic Nucleus (SCN) The SCN is a bundle of nerve cells located in the hypothalamus. It is the main circadian pacemaker, regulating the sleep–wake cycle. It sends signals to the pineal gland, which secretes melatonin. Melatonin levels rise at night to promote sleep and fall in the morning. 🔬 Animal Research: DeCoursey et al. (2000) Destroyed the SCN in chipmunks. Returned them to the wild, and many were killed by predators — they were awake at dangerous times due to loss of their natural sleep–wake rhythm. Shows the SCN is vital for survival and behavioural regulation. ➤ What Are Exogenous Zeitgebers? Exogenous zeitgebers are external environmental cues that help regulate biological rhythms, synchronising them with the outside world. ☀️ Key Example: Light Light is the most important zeitgeber. It resets the SCN each day to keep the circadian rhythm in time with the environment. Light can even affect people through closed eyelids. ➤ Research: Campbell and Murphy (1998) Shone light on the back of participants' knees. Their sleep–wake cycles were shifted by up to 3 hours, showing light can influence biological rhythms without entering the eyes. 👃 Other Zeitgebers: Social cues, meals, routines These can also influence circadian rhythms (e.g. adjusting to jet lag). 🔸 AO3: Evaluation of Endogenous Pacemakers and Exogenous Zeitgebers ✅ 1. Support from Animal and Human Research Animal studies (e.g. DeCoursey et al.) and human studies (e.g. Siffre’s cave study) show that endogenous pacemakers are important in regulating biological rhythms, even in the absence of external cues. These findings support the role of internal clocks, like the SCN, as biologically hardwired mechanisms that drive behaviour. ❌ 2. Issues with Animal Research – Ethical and Generalisability Studies like DeCoursey's involve ethical concerns, as animals were harmed and left vulnerable. There's also a problem of generalising findings from animals (e.g. chipmunks or hamsters) to humans. Human biological rhythms are influenced by social and cognitive factors, so direct comparisons are limited. ✅ 3. Practical Applications – Shift Work and Jet Lag Understanding how endogenous pacemakers and exogenous zeitgebers interact has practical value in areas such as managing shift work, light therapy for SAD, and minimising jet lag. These applications show how psychology can improve health and well-being by manipulating environmental cues to regulate rhythms. ❌ 4. Overstating the Role of Exogenous Cues Some research shows biological rhythms persist without external cues, suggesting endogenous pacemakers may be more dominant. For example: Siffre’s cave studies showed a natural sleep–wake cycle continued without any light or social cues, though it lengthened slightly (~25 hours). This implies exogenous zeitgebers are not essential, but instead act as fine-tuners, keeping rhythms aligned with the environment. ✅ 5. Light as a Powerful Zeitgeber The Campbell and Murphy study highlights that light can influence rhythms even through the skin, supporting the idea that it’s a powerful zeitgeber. However, the study has faced replication issues and methodological concerns (e.g. light might have reached the eyes), so its conclusions should be treated with caution. ❌ 6. Reductionism – Ignoring Interaction Much research isolates either pacemakers or zeitgebers, but in real life, these systems interact constantly. A more valid approach might be an interactionist model, which recognises that both internal and external factors combine to regulate rhythms. Solely focusing on one system is biologically reductionist.